The timestamp column seems to be be in Central European (CET) time, not UTC as claimed, i.e. there is a "missing" hour in March and a "duplicated" hour in October, ie.e in 2013:
| rowid |
utc_timestamp |
| 291433 |
2013-03-31T00:00:00Z |
| 291434 |
2013-03-31T02:00:00Z |
|
|
| 296472 |
2013-10-27T00:00:00Z |
| 296473 |
2013-10-27T01:00:00Z |
| 296474 |
2013-10-27T01:00:00Z |
| 296475 |
2013-10-27T02:00:00Z |